An organic polymer containing at least one reactive silyl group in a molecule is known to have a characteristic that it is cross-linked by siloxane bond formation involving hydrolysis or other reactions of the reactive silyl group due to factors such as moisture even at room temperature, and thereby a rubbery cured product is obtained.
Among such reactive silyl group-containing polymers, organic polymers with a main chain skeleton of a polyoxyalkylene polymer or a polyacrylate ester polymer are described in documents such as Patent Literature 1 and Patent Literature 2, and have already been industrially produced and widely used in applications such as sealing materials, adhesives, and coating materials.
Curable compositions containing these reactive silyl group-containing organic polymers are cured by means of a silanol condensation catalyst, and in the case of one-pack curable compositions, organotin catalysts having carbon-tin bonds, such as dibutyltin bis(acetylacetonate), are widely used. However, conventional organotin catalysts bring problems of low recovery and low creep resistance to the curable composition.
Patent Literature 3 describes a technique of improving water-resistant adhesion using a curable composition that contains as an organotin curing catalyst an organotin compound having a specific structure.